Dec. 7, 2007
A couple studies have been published that have ended the debate over human embyronic stem cell research, because scientists showed how to get embryonic-like stem cells without harming or destroying embryos or cloning human embryos for research. For a summary, continue reading below.
Induced Pluripotent Stem Cells (iPS cells)
Embryonic Stem Cells without Embryos or Eggs
WHAT SCIENTISTS HAVE DONE
Dr. James Thomson of U WI (first to grow human ESC) and Prof Shinya Yamanaka from Japan each have a high profile paper released Nov 20 (in Science & Cell). Both show that embryonic-type stem cells can be produced directly from ordinary human cells, such as a skin cell, without first creating an embryo.
Prof. Yamanaka published a second paper Nov 30 in Nature Biotechnology in which he achieved the same result with human and mouse cells by adding only 3 genes, omitting one gene (myc, an oncogene) that had cancer-causing potential.
Both groups used viruses to add the genes, another potential concern for cancer, but they are already working on refining the technique to eliminate use of viruses.
The "direct reprogramming" technique, first developed by Yamanaka in mice in 2006, involves adding 3-4 genetic factors to an ordinary cell, such as a skin cell. These "reprogram" or "dedifferentiate" the cell directly into an embryonic-type stem cell (called "iPS cells"--induced Pluripotent Stem cells.)
They DO NOT start with adult stem cells, and they DO NOT produce adult stem cells. These are EMBRYONIC-type stem cells.
The technique DOES appear to hold the ethical line: no embryos created or destroyed, no cloning, no eggs needed.
However, it still produces embryonic-type stem cells. So, these will still have all the practical scientific problems that "original" embryonic stem cells have-- tumor formation, problems with getting desired functional cells, and as yet no proof that they will make a transplant match.
These cells cannot form an embryo by themselves. There has been some discussion about the reports that mice were produced from the mouse iPS cells. This is not forming an embryo directly from the cells, but by two techniques that are used to test the pluripotent ability of any ESC. The cell is either injected directly into an existing blastocyst-stage mouse embryo, or a tetraploid embryo is formed by combining the cell with other cells. The mouse embryo is then placed into the womb of a surrogate mouse mother, gestated, and the born mice are examined to see if the ESC or iPSC contributed to all tissues.
Coupled with the announcement by Ian Wilmut (the "father of Dolly") that he is abandoning cloning as a method, in favor of Yamanaka's method to get embryonic stem cells directly, these are significant announcements.
Wilmut, Thomson, and Yamanaka should be CONGRATULATED on turning from questionable science that has produced no useable results, to focus on more promising scientific methods, easier, cheaper, and available for funding now, that also meet the ethical bar (though realistically, Wilmut & Thomson still have no problem with embryo destruction--they are doing this for the scientific advantage.)
These events indicate there is no need to destroy embryos, nor cloned embryos for research.
We should push to ban all human cloning (S. 1036, Brownback-Landrieu; H.R. 2564, Weldon-Stupak), and we should not force taxpayers to fund research that requires the destruction of human embryos. Instead, we should shift resources to fund ethical research. Scientists that want embryonic stem cells can have them without embryo creation or destruction.
We need Congress to pass the Patients First Act (H.R. 2807, Forbes-Lipinski), because ADULT STEM CELLS are still the only stem cells actually benefitting thousands of patients right now and showing any real promise to do so in the near future.
Do we still need embryos and cloning? Answering Common Claims about iPSCs
By Gretchen Vogel ScienceNOW Daily News 20 November 2007
By GAUTAM NAIK WSJ November 20, 2007 9:16 a.m.
By GINA KOLATA NYTimes November 21, 2007
Roger Highfield reports that the alternative to cloning continues to show promise; The Telegraph (London) 7:01pm GMT 30/11/2007
Adult skin cells turned to pluripotent stem cells without a cancer-causing agent
David Cyranoski, Naturenews Published online 30 November 2007